1. Field of the Invention
The present invention belongs to the technical field of light modulation technology, and specifically relates to the micro/nano processing field based on laser direct writing and light modulation based on liquid crystals, in particular to a method for the orientation of liquid crystals in a micro/nano region on the basis of laser direct writing and a system thereof.
2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 37 CFR 1.98.
Liquid crystal display (LCD) technology is applied to various products in the world, for example, watches, cellular telephones and computers. Upon estimation, the production value related to this industry is tens of billions USD every year.
In applications to display on the basis of liquid crystals and to other devices, orientation of the liquid crystals is always a key technique. A basic requirement for manufacturing the liquid crystal displays is the orientation of liquid crystal molecules (hereinafter referred to as “orientation layer”) on a substrate surface (hereinafter referred to as “orientation surface”). Before forming of a liquid crystal box, liquid crystal molecules are placed on the orientation surface. A common method for generating this orientation surface is as follows: covering the substrate surface with a layer of film, for example, polyimide film, and then rubbing the film surface with a piece of polyester velvet. Through rubbing, the polyimide surface performs orientation again to form the orientation surface. The orientation surface provides an orientation cushion for the orientation of the liquid crystal molecules contacting the orientation surface.
In the recent thirty years, the rubbing method has become a main process for providing the orientation surface to the LCD. However, powder from the velvet is needed during the rubbing, and rubbing can generate static charges which damage the transistors below the polyimide surface, thus affecting the working performance of the modern LCD. Therefore, providing a method for forming the orientation surface without endangering the normal working of those transistors is very important. It is acknowledged in the industrial field that, for the future manufacturing engineering, a non-contact or a non-rubbing surface orientation method is a very urgent need for people.
An U.S. Pat. No. 5,770,826 granted to Chaudhari et al. discloses a non-contact method, namely changing the surface of a major type of materials by using low-energy electronic beams to cultivate the orientation for forming the orientation layer. Such orientation or the orientation order drives the liquid crystal molecules to perform directional alignment. Experience shows that LCD can be manufactured according to those inventions.
A strong thrust force in the liquid crystal display technology is improvement on the visual quality of the entire liquid crystal display. However, how to control the parallelism of the liquid crystals is unknown. Parallelism is a key factor for obtaining the homogeneity of the liquid crystal display. Chinese patent No. 01116589.8 “Method and Device for Forming Orientation Layer of Liquid Crystals” and Chinese patent No. 200510130415 “Method and Device for Forming Orientation Layer of Liquid Crystal Display” both study the orientation of the liquid crystals and achieve some progresses. But, they are applicable to the orientation of the liquid crystals in a small area, and inapplicable to the large area case.
Aiming at the orientation of the liquid crystals in a large area, mechanical methods are always employed in the existing liquid crystal industrial technologies and researches to form the orientation layer on the substrate surface to induce orientation of the liquid crystals. But, intrinsic defects and foreign matter pollution in the mechanical orientation method are key factors always affecting the orientation intensity and uniformity of the liquid crystals. To obtain quality orientation of the liquid crystals in a large area is always a technical problem to be broken through.